http://www.instructables.com/id/Synesthesia-Mask/
EXCERPT: What if I told you that 2+2=Red!?!? What!?! I know this sounds crazy but for people with synesthesia this might be their reality. [...] people with synesthesia have blended senses. The most common type of synesthesia is called grapheme, in which numbers and letters are intuitively linked with color. [...] There are a myriad of other types of synesthesia which you can read about [...] but in this Instructable we are going to be designing a mask that links our sense of color with our sense of smell. Get ready to experience the world in a totally new way! List of Necessary Materials...
EXCERPT: What if I told you that 2+2=Red!?!? What!?! I know this sounds crazy but for people with synesthesia this might be their reality. [...] people with synesthesia have blended senses. The most common type of synesthesia is called grapheme, in which numbers and letters are intuitively linked with color. [...] There are a myriad of other types of synesthesia which you can read about [...] but in this Instructable we are going to be designing a mask that links our sense of color with our sense of smell. Get ready to experience the world in a totally new way! List of Necessary Materials...